Column 2 of triangle in A331431.

Terms

a(0) =30a(1) =-180a(2) =630a(3) =-1680a(4) =3780a(5) =-7560a(6) =13860a(7) =-23760a(8) =38610a(9) =-60060a(10) =90090a(11) =-131040a(12) =185640a(13) =-257040a(14) =348840a(15) =-465120a(16) =610470a(17) =-790020a(18) =1009470a(19) =-1275120a(20) =1593900a(21) =-1973400a(22) =2421900a(23) =-2948400a(24) =3562650a(25) =-4275180a(26) =5097330a(27) =-6041280a(28) =7120080a(29) =-8347680